


It's always been you

by emmadilla



Category: Supernatural
Genre: Alpha Dean Winchester, Alpha/Beta/Omega Dynamics, Bottom Castiel (Supernatural), Bottom Castiel/Top Dean Winchester, First Time, Knotting, M/M, Mating, Mating Bites, Mating Bond, Omega Castiel, Scenting, Top Dean Winchester
Language: English
Status: Completed
Published: 2018-12-25
Updated: 2018-12-25
Packaged: 2019-09-27 09:03:28
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,113
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/17159153
Author URL: https://archiveofourown.org/users/emmadilla/pseuds/emmadilla
Summary: When Dean and his girlfriend, Lisa, turn 25 and realise that they aren't each others' mates, they're both crushed and are forced to move on. He soon realises, however, that his real mate may be right under his nose in the form of his friend and roommate, Castiel ...





	It's always been you

**Author's Note:**

  * For [ZarauthForsaken](https://archiveofourown.org/users/ZarauthForsaken/gifts).



> Merry Christmas, Z!

Dean relaxed onto his back, now that his knot had lost enough of its swelling to pull out. Lisa shifted and purred beside him, mostly asleep from their bedroom activities. Smiling at the small movement, Dean turned his head, burying his nose in her hair and sniffed, long and deep. It was something he did after every time he had sex, no matter who it was with. He wasn’t sure if it was an Alpha tendency or if it was just him, but he loved the smell of his partner post-sex. It was … well, for lack of a better term, heavenly. Their scent, mingled with his, along with sweat and various other fluids that clearly denoted what they’d been up to. It was just the right stink, and in the afterglow, it was perfect.

 

Except this time, it wasn’t.

 

His brow furrowing, he sniffed again, even deeper than before, but it didn’t change. There was something … off. He couldn’t even put his finger on it, but it was definitely different than it had been before. Was she using a new shampoo? No, no, he still smelled the faint scent of apples underneath everything else, the same thing she’d been using since before they started dating, so that wasn’t it. Maybe some new product? A new lotion? _Yeah, maybe that’s it_. He laid his head back on the bed and let himself drift into the doze, trying to push this new revelation to the back of his mind.

 

And, for a while, he succeeded. Whenever they hung out or had a meal together or did anything else where they weren’t in too close proximity, it was just like when they first met … young and fun and fast and flirty. Sure, most people didn’t settle down until their scents finally settled at 25 and their noses became more discerning between their friends and their mates, but still … what they had was a good thing, and Dean enjoyed spending time with her. But whenever they were close, whenever he could get a whiff of her, he knew. It was a little early for him, as they were both still several months away from 25, as they shared a birthday, but that didn’t change facts.

 

Sometimes Dean cursed this life. Cursed that Alphas and Betas and Omegas were a thing. Once they presented at 16, they were shipped off to schools and surrounded by their own kind until they got their ruts or heats under control, at age 20. Unless they were a Beta, who were sterile and whose scents were minimal. They were allowed to graduate and leave school early and pursue whatever form of employment they wished. _Freedom_. He’d wanted so badly to be a Beta, for all of his friends to be Beta, so none of them would have to deal with all of the issues surrounding being an Alpha or Omega. Out of their group of friends, Charlie was the only one lucky enough to draw that particular card. Both Dean and his brother ended up being Alphas, and their friends - Cas and Gabe - were Omegas. That meant they had to immediately cut all contact until graduation, not even direct letters in case scent was transferred. Instead, they had to send letters to Charlie first, who would leave the letters in isolation to get rid of any scent before she copied them down and mailed them to the recipient, just to make sure there was no scent transfer. She was a godsend, and the only reason all of them had managed to stay in contact at all. After he and Cas graduated and was adjusting back to life in the world, they’d even gotten an apartment together, in the same complex as Charlie, their friendship unchanged by the passage of time and the limited communication. But still, Dean would have rather not gone through all of that.

 

As with most Alphas and Omegas straight out of school, he’d been eager to … explore his sexuality. After all, they had about five years until all of their scents settled and their noses fully attuned, so nobody was expected to find their mates immediately. Most relationships were pretty casual. Lisa was the closest thing he’d had to anything steady, and for a while he figured why not? She was nice, she was fun, she cared about Dean, and Dean cared about her. But once her scent started to change, it just wasn’t the same, and he couldn’t keep up the ruse forever.

 

He waited, however, just to be sure. After all, if his nose was still adjusting and settling down and her scent was still finalising, it could just all be part of the process. Yeah, the process. The fucked up, cursed processed he’d hated since the day he turned 16. So he stuck with it, held out over the next few months, holding on to the hope that on _that_ day, they would wake up, roll over, and smell their mate. He wanted to so badly. Lisa was sweet and deserved to be loved and Dean wanted to be the one to do that.

 

However, when they both woke up that morning, sleepy and drowsy from their late night tryst, they looked into each other’s eyes and knew. Lisa cried and Dean comforted her, holding her close just like he’d done so many times before. But this time, it was the last time, and Dean was angrier than ever at this hand life had dealt them. They had been so happy together, what was wrong with that? Whatever was wrong with people being happy with each other? And yet, if two people who weren’t mates forcefully marked each other as mates, it signalled a lifetime of struggle for both of them, something that neither of them would wish for the other. It simply wasn’t worth the crippling depression and anxiety that was a guarantee in a forced mating. And so, after they both got up and Dean got dressed, he kissed Lisa on the forehead, gathered the few things he’d had at her apartment, and left. For good.

 

Throwing his belongings in the front seat, he punched the steering wheel and took a deep breath as he calmed down. While most people dreamed of being an Alpha or Omega, he had been one of the few that truly craved the life of a Beta. They might be limited in some ways, but in his eyes, they had the freedom and stability he craved. The ability to just _be_ , separate from their secondary identity. But there was nothing for it. Nature had spoken and he was an Alpha and Lisa wasn’t his mate. It was just the way things were. Turning the key in the ignition, Dean pointed the Impala toward his own apartment complex, wanting to escape for a little while before Charlie inevitably dragged him out somewhere to celebrate. Shaking his head, he couldn’t help the small smile that cracked across his face as he approached his apartment door at the thought of her and her wild smile and her crazy antics.

 

As soon as he walked into the apartment, however, he stopped completely, his hair standing on end as every muscle in his body tensed. He took an experimental sniff and it was then, it was then he smelled it … _Mate_. But there was no one else in the apartment, save for his friend Castiel. Could it be … could his mate really be his best friend? No, it … it couldn’t be as simple as that. It just couldn’t. After all, Cas hadn’t turned 25 yet, so his scent hadn’t settled. His birthday was several months away, and in that time, it could warp and change. As much as Dean wanted to knock on his friend’s bedroom door and tell him, he couldn’t bring himself to do that, couldn’t bring himself to go through another potential heartache. Not again. So, instead, he went to his own room and closed the door, lying down on the bed as he tried to get as much rest as he could before Charlie insisted they go celebrate.

 

Dean kept this secret to himself, despite day in and day out being forced to breathe in the very scent that was driving him crazy. He wanted to pull his hair out, climb the walls, something, _anything_ to relieve the urge to claim his mate and seal their bond. A few times he almost gave up, almost gave in and told him, but each time he stopped, reminding himself of how he felt after leaving Lisa’s place that morning, not wanting to experience that a second time. He just had to wait, just had to stick it out long enough to make it to Cas’ birthday, and then he would know for sure. If they were mates, then great, fantastic. If not, then he could move on and tuck away this secret in his little broken heart, never telling a soul about it.

 

The night before Cas’ birthday, Dean could barely sleep, tossing and turning, grabbing snatches of sleep here and there but never really settling down into a restful sleep cycle. Instead, in the early morning hours, he finally stopped pretending and threw his blankets off of him, resigning himself to an early rise. He yawned as he slowly walked to the kitchen, pouring some water in the coffee maker and setting everything up to brew himself a cup. He parked himself by the window, watching the sun rise as the smell of coffee started to permeate throughout the apartment. Rubbing his arms to rid himself of the slight chill in the air, he poured himself a generous cup, dumping in a small couple spoonfuls of sugar before taking a nice, long sip. _Ah, now that’s the stuff_. The warm liquid permeated through his bones, waking him up just a little bit more. He stood there in front of the window, casually drinking from the large mug as the world around him stirred and woke and readied for the day, a day that was like any other for everyone else, but one that was momentous for Dean. This was the day he would finally find out, the day that he’d been waiting for since he turned 25, and he had only to wait for his roommate to wake to determine the truth. These last hours that he had left to wait felt like forever.

 

He had drank about two-third’s of his cup when suddenly, soft movement behind him had his hairs standing on end. He whirled around to see his roommate standing in the middle of the living room, having emerged from his room much earlier than normal. Cas was standing stock still, eyes wide, looking at Dean, whose heart was clenching in his chest. Their nostrils flared, taking in each other’s scent, and Dean searched, looking for any hint that it was different than it had been this whole time. But it wasn’t. It was the same as it had always been for him. And Cas, well … based on the look on his face, Cas was realising what Dean had subconsciously known this whole time. “You,” he breathed.

 

Dean’s tongue felt like it was stuck to the roof of his mouth, and he swallowed hard, setting the mug down on the table. He watched his Omega friend approach him slowly, and they were looking at the other like it was the first time they’d really, actually seen the other, in ways that they’d never seen before.

 

As Cas stood right in front of him, he reached out and settled a palm against Dean’s face. “You’re …” he started to say and then stopped, not really needing to say the rest. They both knew now. “How long have you known?”

 

His tongue darted out to wet his suddenly dry lips as he replied, “Since my birthday.”

 

“That long?” Castiel exclaimed. “Why haven’t you said anything?”

 

“I …” Dean paused and cleared his throat before he continued, “… I didn’t want to be wrong again.”

 

Cas nodded, knowing how much the break up with Lisa had affected Dean. While a lot of young Alphas and Omegas played around - par for the course, really - once they started approaching 25, feelings could become more complicated. It was one of the reasons that Cas had simply abstained from all of that from the beginning, and no amount of light teasing from Dean or his brother could convince him to give in. He’d wanted his first time to be with his mate, now that his birthday was here, well … his mate was standing right in front of him. His 25th had initially been an arbitrary deadline, something he thought would come and go with little pomp - aside from whatever shenanigans Charlie would bring - but he wasn’t expecting to find his mate _immediately_. Certainly not like this, standing in their kitchen, _waiting_.

 

It seemed like the whole earth stood stood as they both started to lean close to each other, slowly closing the space between them until their lips brushed against each other’s and then everything finally took a breath.The weight that Dean had been carrying finally lifted as they lost themselves in each other. Their scents mixed and mingled with each other, complementing as they formed a bouquet that was uniquely and perfectly _them_.

 

Stumbling to the bedroom, lips locked, they pawed at each other’s sleep clothes until they were eventually able to strip the other. As Cas laid back on his bed, Dean hovering over him, surrounded by his scent, he didn’t think he’d ever seen such a beautiful sight before. All this time that he’d spent waiting until his 25th birthday, wondering who his mate would be, and it was under his nose the entire time in the form of his friend and roommate. Serendipitous didn’t even begin to cover it, this was just _fate_.

 

Dean didn’t simply hover over him forever, lowering himself so he could be lost once more in Cas’ lips before he lightly rutted against him. They were both painfully aroused, their instincts kicking into high gear as Cas started leaking slick. He moaned to feel Dean’s Alpha cock slide against his own, knowing that soon, very soon, it would be buried inside him. And oh how sweet that would be. He’d used toys to satisfy him during his heats, but had never before taken an actual Alpha. Dean was the first, and he would be the only, and he pawed at the man above him as he was suddenly eager for it. He’d waited long enough. They both had. And now that they had found themselves in each other, they wanted to move to consummate it as quickly as possible, as mates were often want to do. Next time, they would go slower, tease each other, learn and map out each and every sensitive spot that littered their bodies. But this time … this time they were driven by intense need, and they couldn’t pace themselves.

 

While he wasn’t unnecessarily rough, Dean didn’t attempt much prep as he slid into Cas. He just went as slow as he possibly could, letting the Omega adjust to his size until he finally bottomed out. It was at this moment that he finally found the patience within him, and he peppered his Omega’s face with soft kisses as Cas breathed deeply and relaxed, his body naturally accommodating to Dean, to _his_ Alpha. Their foreheads rested against each other as Dean finally started to move, started to grind his hips and slide in and out of Cas. The Omega’s eyes fluttered closed as he moaned, wrapping his legs around Dean to try to get him even closer. He felt impossibly full and yet wanted more, _needed_ more as his fingernails dug into the Alpha’s back. Dean groaned in response, nipping along Cas’ jawline as his hands wandered over his mate’s body, relishing the feel of skin on skin.

 

He couldn’t hold back for long, however, and their first time was hot and fast and hard, but it was everything they wanted and everything they needed. As Dean reached between them to stroke Cas’ own member, it felt like everything was coalescing between them, that the world was finally sliding into focus for the first time and it was borderline overwhelming. His knot was starting to swell and he was determined to keep going for as long as he could, but it wasn’t going to be for too much longer. It wasn’t going to be that long for Cas, either, as he moaned and mewled beneath him, baring his neck in preparation for the end. Dean clenched his teeth at the sight, fighting the urge to finish, but his knot caught on Cas’ hole and a shudder ran through his whole body. Lunging forward, he sank his teeth in his mate’s neck, marking him as he came deep inside him. Cas shivered as his own orgasm overtook him, the feel of Dean’s teeth on his neck and his knot now firmly shoved inside him enough to push him over the edge.

 

As they both came down and Dean shifted onto his side, pulling Cas close to him as they waited for the knot to deflate, they traded gentle kisses and soft caresses. Castiel grinned as he murmured, “I can’t believe it was _you,_ but I’m glad it was.”

 

Dean returned the smile. “I can’t really believe it, either. When I walked in the door that morning … I wasn’t really sure what to think, you know? My old friend … my mate? But, I guess, it makes sense in a way … it’s always been you.”

 

They greeted the morning wrapped up in each other, even after Dean’s knot finally deflated and they could physically part. Now that they had each other, they didn’t want to separate again, not for anything. Nothing else in the world mattered, only the two of them in that bed. It was all they needed.

 

Well, until the door suddenly swung open and Charlie yelled, “Surprise!” Balloons scattered as she let go of the strings, her eyes bugging as the two, naked men scrambled for something to cover themselves, the blanket long kicked to the floor and their clothes strewn throughout the room. Embarrassment aside, it turned out to be the best, most entertaining birthday Cas had had for a long time, possibly his entire life, spent with one of his best friends and his newly bonded mate. It was certainly one Dean would never forget. And, despite how much Charlie would want to try to forget it, it was lovely to see her two friends bonded, like it was always meant to be.


End file.
